U4 APES Earth systems & Resources

Planet formations

Planet formed 4.6 billion years ago

Heavier elements (Iron & Nickel sank
toward the center)

Lighter elements like silicon & oxygen
floated to the top

Some gases left the solid part &
became part of the atmosphere

Earths Core

innermost zone of the planet

(nickel & iron) inner core is solid.

Outer core is liquid. The interaction between
the two form magnetic field

Mantle

above core. Contains magma where
convention currents occur. The spongy
material movement drive plate tectonics

Crust

outermost layers of the planet;
thinnest layer contains basement rock of
ocean & continents.

Lithosphere

The brittle outermost layer of the Earth

Asthenosphere

Outer part of the mantle (Semi-molten, Flexible rock)

Crust (continental)

Mostly granite, Si, O

Crust (Oceanic)

Mostly Basaltic, Fe & Mg

Convection

Convection in the Earth happens in the mantle, the layer beneath the crust. It involves hot rock rising and cooler rock sinking, creating convection currents.

Hot spots

Places where molten material from the mantle reach the lithosphere

Continental Drift

Continental drift is the theory that the Earth's continents were once connected as a single supercontinent called Pangaea, and over millions of years, they slowly moved apart to their current positions.

Theory of Plate tectonics

The theory of plate tectonics explains how the Earth’s outer shell (the lithosphere) is divided into large, rigid plates that move over the semi-fluid asthenosphere below. These movements are responsible for many geological phenomena like earthquakes, volcanoes, and the formation of mountain ranges.

Divergent Plate boundaries

When plates move apart from one another

Convergent Plate boundaries

When the plates move towards one another

Transform Fault Boundaries

Plates Move sideways past eachother

Volcano formation

As a plate moves over a hot spot, rising magma forms a volcano

Faults

A fault is a crack or fracture in the Earth’s lithosphere where two blocks of rock have moved relative to each other. Faults are created by stress and are often the cause of earthquakes.

Earthquakes

occurs when the rocks across of the lithosphere unexpedly rupture along a fault

Soil

Soil is the top layer of Earth’s surface where plants grow. It’s made up of a mixture of minerals, organic matter (like decayed plants and animals), air, and water.

Soil formation

Soil formation begins
when bedrock is broken
by physical, chemical, &
biological processes
called weathering

Soil components

Pore space 50% (air/water)

Soil Space 50% (Mineral matter & Organic Matter)

Soil Properties (Texture)

Clay, Sand, & Silt

(Ex. If a soil sample contains: (Silty Clay)

• 30% clay

• 10% sand

• 60% silt

Soil Texture

Largest → Smallest

Sand → Silt → Clay

• Sand = easily seen

• silt = size of flour

• clay = electronic microscope

O horizon

composed of organic detritus in various
stages of decomposition.

A horizon

topsoil, a zone of organic material &
minerals that have been mixed together.

E horizon

Zone of leaching, found in some acidic soils
under the O horizon or, less often, the A horizon.

B horizon

primarily of mineral material with very little
organic matter.

C horizon

least-weathered soil horizon, always
beneath the B horizon, & similar to the parent material.

Eutrophication

Eutrophication is when a body of water becomes overly rich in nutrients (like nitrogen and phosphorus), often due to runoff from fertilizers, sewage, or animal waste.

Desert soil

• Soil: Very dry, sandy, and low in organic matter.

• May have salts from evaporation.

• Poor for farming without irrigation.

Grass land soil

• Soil: Deep and nutrient-rich, especially in temperate grasslands (like prairies).

• Great for growing crops—often used in agriculture.

• Lots of roots from grasses add organic material.